J/A+A/641/A95 NGC 4104 g and r CFHT/Megacam images (Lima Neto+, 2020)
NGC 4104: A shell galaxy in a forming fossil group.
Lima Neto G.B., Durret F., Lagana T.F., Machado R.E.G., Martinet N.,
Cuillandre J.-C., Adami C.
<Astron. Astrophys. 641, A95 (2020)>
=2020A&A...641A..95L 2020A&A...641A..95L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Photometry, SDSS
Keywords: galaxies: individual: NGC 4104 - galaxies: groups: general -
galaxies: photometry - X-rays: galaxies - methods: numerical
Abstract:
Groups are the most common association of galaxies in the Universe and
they are found in different configuration states, such as loose,
compact, and fossil groups.
We studied the galaxy group MKW 4s, dominated by the giant early-type
galaxy NGC 4104 at z=0.0282, with the aim of understanding the
evolutionary stage of this group and to place it within the framework
of the standard ΛCDM cosmological scenario.
We obtained deep optical data with CFHT/Megacam (g and r bands)
and we applied both the galfit 2D image fitting program and the
IRAF/ellipse 1D radial method to model the brightest group galaxy
(BGG) and its extended stellar envelope. We also analysed the publicly
available XMM-Newton and Chandra X-ray data. From N-body simulations
of dry-mergers with different mass ratios of the infalling galaxy, we
were able to constrain the dynamical stage of this system.
Our results show a stellar shell system feature in NGC 4104 and an
extended envelope that was reproduced by our numerical simulations of
a collision with a satellite galaxy taking place about 4-6Gyr ago.
The initial pair of galaxies had a mass ratio of at least 1:3. Taking
into account the stellar envelope contribution to the total r band
magnitude and the X-ray luminosity, MKW 4s falls into the category of
a fossil group.
Our results show that we are witnessing a rare case of a shell
elliptical galaxy in a forming fossil group.
Description:
Reduced FITS images in g and r bands obtained with MegaCam/CFHT.
More details in the paper.
Objects:
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RA (2000) DE Designation(s)
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12 06 38.91 +28 10 27.2 NGC 4104 = UGC 7099
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 81 2 List of fits images
fits/* . 2 Individual fits images
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix scale Scale of the image
26- 29 I4 --- Nx Number of pixels along X-axis
31- 34 I4 --- Ny Number of pixels along Y-axis
36- 41 I6 Kibyte size Size of FITS file
43- 59 A17 --- FileName Name of FITS file, in subdirectory fits
61- 81 A21 --- Title Title of the FITS file
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Acknowledgements:
Gastao Lima-Neto, gastao(at)astro.iag.usp.br
(End) Patricia Vannier [CDS] 08-Jul-2020